<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>test-2</title>
    <style>
        body {
            margin: 0;
        }
        button {
            border: 1px solid #ccc;
        }
        h3 {
            padding: 0;
            margin: 0;
        }
        .w {
            width: 1200px;
            margin: 0 auto;
        }
        .header {
            height: 80px;
            line-height: 80px;
            background-color: #f0f0f0;
        }
        .btn-alert {
            padding: 10px 20px;
            cursor: pointer;
            vertical-align: middle;
            border-radius: 4px;
            background-color: deepskyblue;
            color: #fff;
        }

        .mask {
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, .5);
            position: fixed;
            top: 0;
            left: 0;
            z-index: 1000;
            display: none;
        }
        .mask-box {
            width: 420px;
            height: 200px;
            background-color: #fff;
            position: absolute;
            left: 50%;
            top: 50%;
            margin-top: -100px;
            margin-left: -210px;
        }
        .mask-box h3 {
            text-align: center;
            line-height: 50px;
            height: 50px;
        }
        .mask-box .btn-close {
            width: 30px;
            height: 30px;
            position: absolute;
            right: 10px;
            top: 10px;
            font-size: 20px;
            cursor: pointer;
        }
    </style>
</head>
<body>
    <div class="header">
        <div class="w">
            <button class="btn-alert">弹出</button>
        </div>
    </div>

    <!-- 弹窗 -->
    <div class="mask">
        <div class="mask-box">
            <h3>标题: 自定义弹窗<span></span> </h3>
            <button class="btn-close">×</button>
            <div>

            </div>
        </div>
    </div>

    <script type="text/javascript">
        // 分值：10分
        // 要求：
            // 自定义弹窗
            // 点击"弹出"按钮，显示弹窗
            // 点击"x" 按钮，隐藏弹窗

        
         // 评分：可有多种实现方式，实现功能即可！


    </script>
</body>
</html>